class_docstr: Network Server Class
      
docstr: Keeps track of the number of connections and time of the last one
docstr_tok: ["Keeps","track","of","the","number","of","connections","and","time","of","the","last","one"]
code: def ncon_add(self, val):
      """Keeps track of the number of connections and time of the last one"""
      self.ncon_lock.acquire()
      self.ncon += val
      self.last_con_time = time.time()
      self.ncon_lock.release()
  
imports: import atexit
  import logging
  import errno
  import getopt
  import sys
  import socket
  import threading
  import random
  import string
  import signal
  import time
  import os
  import ppft
  import ppft.auto
  import ppft.common
  import ppft.transport
  import hashlib
label_desc: Use image node_id 2 for calling the _NetworkServer obj's underlying member method code with example usage: obj.ncon_add(val) without return types